2022-04-01 06:38:40

by Dov Murik

Subject: [PATCH v9 3/4] efi: Register efi_secret platform device if EFI secret area is declared

During efi initialization, check if coco_secret is defined in the EFI
configuration table; in such case, register platform device
"efi_secret". This allows udev to automatically load the efi_secret
module (platform driver), which in turn will populate the
<securityfs>/secrets/coco directory in guests into which secrets were
injected.

Note that a declared address of an EFI secret area doesn't mean that
secrets where indeed injected to that area; if the secret area is not
populated, the driver will not load (but the platform device will still
be registered).

Signed-off-by: Dov Murik <[email protected]>
---
drivers/firmware/efi/efi.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 378d044b2463..b92eabc554e6 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -425,6 +425,9 @@ static int __init efisubsys_init(void)
if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
efi_debugfs_init();

+ if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
+ platform_device_register_simple("efi_secret", 0, NULL, 0);
+
return 0;

err_remove_group:
--
2.25.1

2022-04-04 21:37:57

by Dov Murik

Subject: Re: [PATCH v9 3/4] efi: Register efi_secret platform device if EFI secret area is declared

On 01/04/2022 0:56, Dov Murik wrote:
> During efi initialization, check if coco_secret is defined in the EFI
> configuration table; in such case, register platform device
> "efi_secret". This allows udev to automatically load the efi_secret
> module (platform driver), which in turn will populate the
> <securityfs>/secrets/coco directory in guests into which secrets were
> injected.
>
> Note that a declared address of an EFI secret area doesn't mean that
> secrets where indeed injected to that area; if the secret area is not
> populated, the driver will not load (but the platform device will still
> be registered).
>
> Signed-off-by: Dov Murik <[email protected]>
> ---
> drivers/firmware/efi/efi.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 378d044b2463..b92eabc554e6 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -425,6 +425,9 @@ static int __init efisubsys_init(void)
> if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
> efi_debugfs_init();
>
> + if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
> + platform_device_register_simple("efi_secret", 0, NULL, 0);

These two lines should be wrapped by #ifdef CONFIG_EFI_COCO_SECRET .
I'll fix that for the next round.

-Dov

> +
> return 0;
>
> err_remove_group:

2022-04-07 21:05:29

by Gerd Hoffmann

Subject: Re: [PATCH v9 3/4] efi: Register efi_secret platform device if EFI secret area is declared

On Thu, Mar 31, 2022 at 09:56:06PM +0000, Dov Murik wrote:
> During efi initialization, check if coco_secret is defined in the EFI
> configuration table; in such case, register platform device
> "efi_secret". This allows udev to automatically load the efi_secret
> module (platform driver), which in turn will populate the
> <securityfs>/secrets/coco directory in guests into which secrets were
> injected.
>
> Note that a declared address of an EFI secret area doesn't mean that
> secrets where indeed injected to that area; if the secret area is not
> populated, the driver will not load (but the platform device will still
> be registered).
>
> Signed-off-by: Dov Murik <[email protected]>

Reviewed-by: Gerd Hoffmann <[email protected]>